Drill feeding mechanism



4 Sheets-Sheet l Filed Nov. 25, 1938 ATTORNEY Dec. 3, 1940. H. J. sHoRLE 2,223,533

DRILL FEEDING MECHANISM Filed Nov. 25, 1938 4 Sheets-Sheet '2 ATTORNEY Dein 3, 1940. H, J. SCHORLE 2,223,533

DRILL FEEDING MECHANISM Filed Nov. 23, 1938 #Sheets-Sheet 3 Herma/7 J .5o/20de l ENTOR ATTORNEY Dec. 3', 1940.

H. J. scHoRLE: 2

DRILL FEEDING MECHANISM Filed Nov. 23, 1938 4 Sheets-Sheet 4 NR m mm m, E

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Patented Dec. 3, 1940 UNITED 'STATES PATENT OFFICE 2,223,533 Daim. FEEDING MECHANISM Application November 23, 193s, serial No. 241,897

1 Claim.

This invention relates to percussive tools, and `more particularly to feeding means therefor.

An object of the present invention is to provide a drill feeding means for progressively feeding a rock drill or analogous percussive tool to its work or withdrawing. it therefrom which consists of a motive fluid actuated motor carried either by the drill or by its supporting `cradle and which cooperates with a feed screw for progressively feeding the drill steel to its work as the drilling proceeds, and by means of which the drill may be withdrawn from the work for resetting, or upon the completion of a drill hole.

With these and other objects in View, as may appear from the accompanying specification, the

drawings,y showing a drill feeding mechanism embodying the invention, and the features forming the invention will be specifically pointed out in the claim.

In the drawings: Y

Figure 1 is a side elevation of a rock drill having the improved drill feeding means associated therewith. s

Figure 2 is a fragmentary longitudinal section through the drill feeding means taken on the line 2--2 of Figure 4.

Figure`3 is a longitudinal section through the drill feeding motor taken on the line 3-3 of Figure 5.

Figure 4 is an end View of the drill feeding motor having parts removed.

Figure 5 is a cross-section on the line 5-5 of Figure 2.

Figure 6 is a cross-section on the line 5 6 of Figure 2.

Figure '7 is a detailed cross-section of a part of the rock drill showing one manner of connecting the feeding motor actuating fluid supply to the rock drill.

Figures 8, 9 and 10 are diagrammatic cross-sections of the feeding motor control valve showing it in different positions.

Referring more particularly to the drawings, a rock drill or other percussive tool I is shown as mounted upon its guiding and supporting cra dle 2 in any approved manner for longitudinal movement along the cradle. The rock drill I is, in the form shown in the drawings, moved along the cradle 2 by the rotation of the feed screw 3 through the medium of a feed nut 4, as is common practice in feed screw type feeds for percussive tools.

The present invention relates particularly to the mechanism for feeding the rock drill I along the cradle 2, and in the form shown in the drawings, specifically, a fluid actuated or pneumatic motor for rotating the feed screw 3. It is to be understood, however, that by slight changes in the location and arrangement of the improved fluid actuated motor it may be utilized for rotating a feed screw nut relative to a stationary feed screw for feeding a rock drill along the cradle 2, without departing from the spirit of the present'l invention.

The fluid actuatedv feed motor comprises a housing 5 which has a sleeve 6 on its forward end into and through which the ribbed end 'I Aof the feed screw 3 extends. The ribs 8 on the end 'l of the feed screw 3 t in circumferentially spaced grooves 9 in the chuck I0. The chuck Il is rotatably carried within the housing 5 and has peripheral gear teeth II, which are engaged by the gear teeth I2, formed on the gyrating yoke I4 of the reduction gearing which serves to rotate the feed screw 3 and connects the chuck lil to the operating motor structure I5. The gyrating yoke I4 is gyrated in the housing 5, intermittently bringing certain of its internal teeth I2 into meshing, operating engagement with certain of the teeth I I of the chuck I0, as shown in Figure 5 of the drawings. The yoke I4 is engaged by a pair of cams I6 disposed upon opposite sides of the axis of the chuck I0. The cams I6 are carried by shafts Il which extend longitudinally in the housing 5 and have their ends journaled in suitable bearings I8. Keyed upon each of the shafts I1 is a gear I9, the teeth of which mesh with the teeth of the driving or motor gear 2li. The driving or motor gear Ellis rotatably mounted upon a sleeve 2| formed on the head 22 of the housing 5. The gear has a plurality of large abutment teeth 23 formed thereon at circumferentially spaced points about its periphery, and these teeth 23 fit with comparative snugness against the inner wall 24 of the motor chamber,

and the pressure fluid entering the motor chamber through the supply ports 25 impinges against the abutment teeth 23 and rotates the gear 2U, in turn rotating the gears I9, which, through the medium of the shafts II and cams I6 gyrate the gyrating yoke I4 and rotate the chuck I0. The rotation of the chuck I0 will rotate the feed screw 3, which, being engaged by the feed nut 4, will move the rock drill or other percussive toool I forwardly along the cradle 2, feeding the drill steel A to its work. The motive fluid eX- hausts from the motor chamber through exhaust Cil ports 26, and from the exhaust ports 26 through the exhaust recesses 21 in the valve 28 and outwardly through the exhaust ports 29 in the head 22, to atmosphere.

The Valve 28 is in the form of a plug valve, which is rotatably carried by the housing 5, being rotated by means of a handle 29' positioned exteriorly of the rear end of the housing 5. Rotation of the valve 28 is resistedby means of a spring pressed washer 30 which has teeth 3I' thereon. The teeth 3| of the washer 3l] mesh with corresponding teeth on the inner end of the plug valve 28. the plug valve is controlled by stops 3.2 and 33 formed in the head-22 of the housing 5.

Pressure fluid is delivered to the valve 28, in the construction shown in the drawings, from'the throttle plug 34 of the rock drill I, through a suitable flexible conduit 35, which opens into a passage 36 in the housing 5. The passage 36 communicates with an annular groove 31 formed in the plug valve 28. A plurality of radial passages 38 carry the pressure fluid from theannular groove 31 to the axial chamber 39 formed in the plug valve 28. A second pair of radial supply passages extend through the plug valve 28 and open out through flats 4I formed on the periphery of the plug valve. l

In Figure 8 of the drawings the plug valve is shown in neutral position; that is, a position' when the supply of actuating motor fluid to the motor gear 20 is cut off. In Figure 9 of the drawings the plug Valve is shown moved into position, by means of the handle 29', to deliver pressure v fluid to the motor gear 20 for rotating the motor gear in the direction to feed the rock drill I towards its work. At such time the radial ports 40 communicate with the supply ports 25, while the passages 26 communicate with the diametrically opposed exhaust recesses 21 formed in the periphery of the plug valve 28, and through these recesses with the exhaust ports 29 in the head 22 of the housing 5. The second set of exhaust recesses 21' formed in the periphery of the plug valve 28 are in neutral position, or non-operative position, at this time. v

'I'he provision of the flats 4I permit regulation of the speed of operation of the motor gear 2l), and consequently the speed of rotation of the feed screw 3, in that by regulation of the rotation of the plug valve 28 the supply of motive fluid to the motor gear 20 may be controlled by the amount of the area formed by the flats which communicates with the supply passages 25.

When it is desired to reverse the direction of rotation of the feed screw 3 for moving the rock drill I away from its work, the operating handle 29 is moved to the right (of the Figures 8 to 10),

The limits of rotary movement of as shown iny Figure 10 of the drawings. The movement of the handle 29 into a reverse position moves the radial ports 40 and the areas formed by the flats 4I into communication with the ports or passages 26, which in turn communicate with the motor gear so that the direction of rotation of the motor gear 20 will be reversed.

At such time the ports 25 communicate withthe supply of motive fluid to the feeding means is controlled. by the throttle valve of the rock drill, but if it is so desired, the supply of motive iluid to the motor structure may be independent of the throttle valve 45 and controlled completely by the plug valve 28.

v Yieldable means are provided for' establishing a yielding connection between the feed screw 3 and the chuck I0 to compensate for jars caused by the operation of the pneumatic tool or rock drill, and to insureconnection between the ribbed end 1 of the feed screw 3 and the chuck I0. This yieldable means comprises a spring 46 mounted in the sleeve 6, one end of which spring engages a collar 41 formed on the feed screw, while the other end engages an abutment collar 48, which abuts the outer surface of the flange 49 formed at the inner end of the sleeve 6.

A suitable handle 50 is attached to the outer end of the motor housing 5. i

It will be understood thatv the invention is not to be limited to the kspecific construction or arrangement of parts shown, but that they may be widely modied within the invention dened by` thereon slidably extending into said chuck for rotatably connecting the feed screw and chuck,

and yieldable means between said housing and said screw for yieldably maintaining rotary connection between the feed screw and chuck.

HERMAN J. scHoRLE.'

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